Gallium-nitride-based semiconductor devices, such as p-n diodes, p-i-n diodes, Schottky diodes, high electron mobility transistors (HEMTs), can be applied to a variety of power systems, such as solar inverters, compact power supplies (e.g., power factor correction circuits or PFC), switch-mode power supplies (SMPS), motor drives, RF power amplifiers, solid state lighting (SSL), smart grid, and automotive motor drive systems. Accordingly, there is a need in the art for improved methods and systems related to forming gallium-nitride-based semiconductor devices.